1. Field of the Invention
This invention relates to a mechanism for locking the opened state of a foldable baby carriage.
2. Description of the Prior Art
An examination of the history of change of baby carriages with attention paid to their seat sections shows that initially they were of the so-called box type and then changed to the chair type, which has since continued, and baby carriages with chair type seat sections are popular today. In the background of switching from the box type to the chair type, there was a desire for reducing the weight of the baby carriage and making it more compact in the folded state.
Although the chair type baby carriage is convenient for use, the space allotted to its seat section is limited. As a result, the seat section is reduced in size to the extent that it has been difficult to sit or lay a baby there in an easy state.
3. Description of the Related Arts
Thus, considered from the standpoint of a baby, it cannot be denied that it is preferable for a baby carriage to have a box-type seat section or a large seat section equivalent thereto. In this connection, there can be contemplated a skeleton construction for baby carriages, as shown in FIGS. 7 and 8, which allows advantageous attachment of a relatively large seat section and which can be compactly folded. In addition, the baby carriage shown in FIGS. 7 and 8 has not been publicly known yet, but is only described in copending Japanese patent application No. 170416/1985, "Baby Carriage" (filed July 31, 1985).
FIGS. 7 and 8 are diagrammatic side views of an example of a foldable baby carriage to which this invention is applied. In FIG. 1 showing the baby carriage in the opened state, the numeral 1 denotes a front leg as a first leg and 2 denotes a rear leg as a second leg, these front and rear legs 1 and 2 being each provided in a pair. The lower end of the front leg 1 has a front wheel 3, diagrammatically shown, rotatably attached thereto, while the lower end of the rear leg 2 has a rear wheel 4 attached thereto. A seat section (not shown) is positioned so that it extends between the front and rear legs 1 and 2. The seat section may further extend forward and rearward beyond the front and rear legs 1 and 2. Lateral frames 5 are positioned on opposite sides of the seat section. Each lateral frame 5 extends between the front and rear legs 1 and 2 on the same side.
The lateral frame 5, as shown in FIG. 8, is foldable in a lateral plane of the baby carriage. Therefore, when the lateral frames 5 assume the extended state, the front and rear legs 1 and 2 are spaced from each other to establish the opened state of the baby carriage shown in FIG. 7. On the other hand, when the lateral frames 5 assume the folded state, the front and rear legs 1 and 2 move toward each other to establish the closed state of the baby carriage shown in FIG. 8.
In FIGS. 7 and 8, each lateral frame 5 is formed of two foldable lateral rod members 6 and 7. The lateral rod members 6 and 7 are turnably connected at their opposite ends to the front and rear legs 1 and 2 on the same side. Further, the lateral rod members 6 and 7 are disposed side by side and one above the other.
In addition, a push rod 8 for pushing the baby carriage may be mechanically fixed to the rear legs 2, as shown in dotted lines in FIGS. 7 and 8.
Thus, according to the baby carriage shown in FIGS. 7 and 8, the lateral frame 5 itself is foldable, so that even if the lateral frame 5 is increased in longitudinal dimension to lengthen the wheel base between the front and rear wheels 3 and 4 so as to improve the safety feature of the baby carriage and then the seat section is increased in size, the skeleton of the baby carriage can be compactly folded.
Another example of a baby carriage having the same advantage will now be described with reference to FIGS. 9 and 10.
This baby carriage is basically the same as the preceding baby carriage in that it has front legs 1, rear legs 2 and foldable lateral frames 5. Each lateral frame 5 of the baby carriage shown in FIGS. 9 and 10 comprises an upper foldable lateral rod member 16 and a lower foldable lateral rod member 17 which are disposed side by side and one above the other. The upper lateral rod member 16 is turnably connected to the front and rear legs 1 and 2, with its opposite ends extending beyond the front and rear legs 1 and 2. The extended ends of the upper lateral rod member 16 have the upper ends of prop rods 18 and 19 turnable connected thereto. The lower ends of the prop rods 18 and 19 have one of the respective ends of reverse-turn rods 20 and 21 turnably connected thereto, the other ends of said prop rods 20 and 21 being turnably connected to the front and rear legs 1 and 2. The lower lateral rod member is turnably connected at its opposite ends to said one of the respective ends of the reverse-turn rods 20 and 21.
Further, there are provided connecting links 22a and 22b for interconnecting the upper and lower lateral rod members 16 and 17. Thereby, the folding and unfolding movement of one of the upper and lower lateral rod members 16 and 17 is operatively associated with that of the other.
In the two types of baby carriages described above, as can be seen from a comparison between their opened and closed states, when the folding of the lateral frame 5 is inhibited, the opened state of the baby carriage is locked. To achieve such locking, it may be contemplated to provide means for keeping the spacing between the front and rear legs 1 and 2 in its increased state. This will now be described with reference to FIGS. 11 and 12 and in connection with the baby carriage shown in FIGS. 9 and 10.
A locking rod 23 is provided which is turnably connected to at least one of the front legs 1 and the rear leg 2 on the same side. The locking rod 23 is foldable itself and is designed so that its folding can be selectively inhibited. Thus, the arrangement can be made so that unless the locking rod 23 is folded, the closed state as shown in FIGS. 7 and 8 cannot be obtained.
In this connection, to bring the baby carriage now locked in its opened state into its closed state by using such a locking rod 23, first, it is necessary to render the locking rod 23 foldable. Then, as shown in FIG. 12, the closed state of the baby carriage is obtained in which the locking rod 23 together with the upper and lower lateral rods 16 and 17 has been folded.
When the operation for changing the baby carriage from the opened to the closed state is taken into account, it is thought that even if the locking rod 23 is rendered foldable, the locking rod must be operated in the early stage to define the folding direction thereof before it can be actually folded. Otherwise, even if the locking rod 23 is in its foldable state, it could act to resist the front and rear legs 1 and 2 moving toward each other.